The goals of the proposed research are to systematically investigate social information processing capacities in Williams syndrome (WMS). Earlier work has shown that people with WMS have good face processing skills and language ability. While they are not spared on classic theory of mind tasks, studies we conducted in our ongoing research, during the current award period, suggest that they are better than matched comparison groups in reading mental state information in eyes. We plan to extend this work by investigating foundational capacities in adolescents and adults with WMS to process information in two main channels for social communication: faces and vocal prosody. A series of experiments will be conducted with groups of adolescents and adults with WMS, matched on age, gender, IQ and receptive vocabulary to adolescents and adults with non-specific mental retardation, and to age and gender matched non-retarded controls. The experiments test the hypothesis that people with WMS are relatively spared compared to the matched mentally retarded controls in: (A) Face recognition; we also predict that they process faces using the same holistic representations as normal adolescents and adults; (B) Voice recognition; and the use of prosody in linguistic processing of both word and sentence ambiguity; (C) Attributing social-mental state information to faces; (D) Attributing mental state information to vocal prosody; (E) Recognizing people and attributing mental state information to dynamically presented social stimuli; (F) Expressing affect and empathy to dynamically presented emotionally charged events at physiological, and behavioral (but not cognitive) levels. We are especially interested in investigating the relationships between face processing skills and use of linguistic prosody, and parallels in the ability to attribute social or mental state information to faces and prosody -the two primary channels for interpersonal communication and social interaction. Our research also explores these links between faces and vocal prosody in different modalities: in the perception and expression of emotion. These studies will lay the groundwork for future studies that will address how these capacities develop in children with WMS, and the neural bases of these social information processing skills using functional brain imaging methodologies. This research will significantly advance our understanding of the phenotypic characteristics of people WMS, which has important implications for enhancing their everyday lives. Together, this program of research on WMS will provide a unique contribution to theoretical and empirical work in the newly emerging field of social cognitive neuroscience.